(UPI) -- At least one airport worker was killed and three other people were wounded at Los Angeles International Airport Friday when a shooter entered Terminal 3 of the airport and opened fire.

According to NBC News, one TSA employee was killed an another wounded. A Los Angeles Police Department detective confirmed a gunman in custody, a US citizen in his mid-20s, but were not yet releasing his name.

A statement from UCLA Medical Center said one male victim was in critical condition, while two other males were listed as fair. The Los Angeles Fire Department said a total of seven people were treated for injuries, and six were transported to hospitals. The suspect was among the injured, but his condition was not released.

Eyewitnesses describe a man approaching the desk inside the terminal before opening fire.

Officials from LAX said the incident began around 9:30 a.m Pacific. The location or condition of the suspect is unknown, although some reports said he was injured, or in custody. The airport implemented a full ground-stop of all flights.

Terminals 2 and 3 were evacuated when shots rang out at the airport, as was Century Boulevard. Terminal 3 serves Allegiant Air, Frontier, JetBlue, Spirit and Virgin America.

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